Biochar is part of a sustainable solution to climate change, by sequestering carbon and preventing its return to the atmosphere as greenhouse gas carbon dioxide. Biochar has also been documented to improve soil fertility by increasing resident soil carbon with resultant improved microbiological populations. This further amplifies carbon sequestration, as well as improving moisture and nutrient retention. The productive deep prairie soils of the Midwest, and the Terra Preta soils in the Amazon are a result of char.